1. Field
One or more embodiments of the present invention relate to a flat panel display device and a method of manufacturing the flat panel display device
2. Description of the Related Art
Recently, flat panel display devices have increased in popularity. Among flat panel display devices, electroluminescent display devices, which are self-emitting display devices, have attracted attention as the next generation of display devices, because of their wide viewing angle, excellent contrast ratio, and short response time. Organic light-emitting display devices include a light-emitting layer formed of an organic material, and form brighter images, have a lower driving voltage, and a shorter response time, as compared to inorganic light-emitting display devices.
However, a light-emitting unit of the organic light-emitting display device may deteriorate, due to the penetration of moisture. Thus, in order to prevent the penetration of external moisture, an organic light-emitting display device should include an encapsulation structure, so as to seal and protect the light-emitting unit.
According to the related art, an encapsulation structure includes a glass encapsulation substrate formed over a light-emitting unit disposed on a glass substrate. A sealant is used to seal a gap between the glass substrate and the encapsulation substrate. The sealant, may comprise an ultraviolet (UV)-curable material. The sealant is coated around the light-emitting unit, on the glass substrate, to attach the encapsulation substrate to the glass substrate. Then UV rays are radiated to cure the sealant, so that the glass substrate and the encapsulation substrate are tightly adhered to each other.
However, this encapsulation structure uses an expensive glass material as the encapsulation substrate. In order to solve this problem, a solution has been proposed where the encapsulation substrate is formed of a metal, such as stainless steel or aluminum. However, such a metal encapsulation substrate reflects UV rays, making it difficult to use a UV-curable material sealant. In addition, even if a different type of sealant is used, sealants capable of adhering different materials often suffer from degradation over time and/or weak bonding strength.
Thus, there is a demand for a sealing unit that insures a strong adhesion between a low cost metal encapsulation substrate and a glass substrate.